Hi all,
I am setting up a tractor prop plane so I need to get the pitot probe out onto the wing so it isn't affected by propwash. I want to cut down on wires and connectors, so could someone checkout this schematic and let me know if it will work.

Thanks for any help.

The ground connection is common so that's okay but your servo runs on 5v. I don't know if this is the case for the airspeed sensor. Maybe it is 3.3v to be safe why not use the spare pin in your connector and run another wire so you know it is okay.

Hi all,
I am setting up a tractor prop plane so I need to get the pitot probe out onto the wing so it isn't affected by propwash. I want to cut down on wires and connectors, so could someone checkout this schematic and let me know if it will work.

Thanks for any help.

Why play with the wires? Why not leave the electronics in the fuse and run tubing (pitot and static) out to the probe?

This way you only have servo wires and two tubes dangling, ready for connection to the sensors.

I guess the thinking is unplugging 1 plug is easier then unplugging a plug and having 2 silicon tubes to reattach every flight. At a guess

That is exactly what I'm thinking. The manuals for the speed and altitude sensors say they can work as standalone by just connecting the red and white pins to a spare servo outlet and I have just finished checking this with a 4 cell NiCd pack and they both power up fine.

I was checking with a meter and definitely found the negative was common, but i got approx 1.5meg between the red pin on the sensor and the +ve servo rail. This made me wonder about the 3.3v thing as well. There will also be a guardian in the fuse as well. My brain is thinking it will work but my heart is worried about letting the smoke out. maybe Bill will chime in within a couple of days otherwise I will probably just shut my eyes and try it.

The ground connection is common so that's okay but your servo runs on 5v. I don't know if this is the case for the airspeed sensor. Maybe it is 3.3v to be safe why not use the spare pin in your connector and run another wire so you know it is okay.

Forgot to add that i want to keep that spare pin in case I want to add flaps later. The other wing will have one of these plugs as well for its servo and the video tx.

I guess the thinking is unplugging 1 plug is easier then unplugging a plug and having 2 silicon tubes to reattach every flight. At a guess

Yeh putting those silicon tubes onto the barbs is real hard. Will probably take a lengthy 1sec each to fit, and surely only once at the start of the flying day.

All I know is that I'd rather not mess with the low voltage signal wires over distances greater than they need to be. Extending the pitot/static tubes IMHO is far less problematic and also means that the altitude and airspeed sensors ($$$$$$) can be moved from aircraft to aircraft. All you need is another probe and tubing ($) for each aircraft and leave them permanently mounted in each.

Hi all,
I am setting up a tractor prop plane so I need to get the pitot probe out onto the wing so it isn't affected by propwash. I want to cut down on wires and connectors, so could someone checkout this schematic and let me know if it will work.

Thanks for any help.

I think better to run an extra connector for the sensor as I measured the I2C bus voltage and its different to the servo voltage. The sensor doesn't use much current so you wont see any voltage drop if you put the sensor out in the wing.

That is exactly what I'm thinking. The manuals for the speed and altitude sensors say they can work as standalone by just connecting the red and white pins to a spare servo outlet and I have just finished checking this with a 4 cell NiCd pack and they both power up fine.

I was checking with a meter and definitely found the negative was common, but i got approx 1.5meg between the red pin on the sensor and the +ve servo rail. This made me wonder about the 3.3v thing as well. There will also be a guardian in the fuse as well. My brain is thinking it will work but my heart is worried about letting the smoke out. maybe Bill will chime in within a couple of days otherwise I will probably just shut my eyes and try it.

I forgot you could power them as stand alone like that, this means your wiring diagram will work fine

I forgot you could power them as stand alone like that, this means your wiring diagram will work fine

Not really. In stand alone mode the red wire is only connected to the Rx power wire. When connected to the OSD you have shorted the Rx power to the Expander power connection. Like you mentioned earlier I wouldn't short the two power buses. The ground wire is fine but not the power wire.

The manual states "NOTE: The Standalone Cable must not be used when connected to the eLogger!". I also think this implies that you shouldn't.

Not really. In stand alone mode the red wire is only connected to the Rx power wire. When connected to the OSD you have shorted the Rx power to the Expander power connection. Like you mentioned earlier I wouldn't short the two power buses. The ground wire is fine but not the power wire.

The manual states "NOTE: The Standalone Cable must not be used when connected to the eLogger!". I also think this implies that you shouldn't.

Steve

Thanks for that Steve, I missed the note when I was reading the manual, proves that you must not just read the manual, but, read the manual carefully (RTFM). I think the pretty picture caught my attention.

That is exactly what was worrying me when I measured 1M5 between the servo rail and bus power. Extra wire it is then.

Quick question.. I have my ground station setup with 2 x 1.2ghz rx, Eagletree fpv station, antenna tracker with homemade crosshair on it and SPW on the other rx.

I have a problem with it conflicting with my dragonlink UHF. I get noise in my video when i turn my dragonlink on, if i turn rotate the dragonlink controller around 360 degrees, the interference differs, at worst, i completely loose signal, this is 2-3m from the fpv station.

Do i need filters on the uhf tx or filters on the fpv station end?

I'll note here that with my SPW antenna, i get this problem, with the homemade crosshair antenna, it works fine. No interference

Also, if i put the UHF antenna near the antenna tracker, it actually interferes enough to move the pan and tilt servos. Obviously it will never be that close, but its an interesting example of how much interference its throwing out.

Quick question.. I have my ground station setup with 2 x 1.2ghz rx, Eagletree fpv station, antenna tracker with homemade crosshair on it and SPW on the other rx.

I have a problem with it conflicting with my dragonlink UHF. I get noise in my video when i turn my dragonlink on, if i turn rotate the dragonlink controller around 360 degrees, the interference differs, at worst, i completely loose signal, this is 2-3m from the fpv station.

Do i need filters on the uhf tx or filters on the fpv station end?

I'll note here that with my SPW antenna, i get this problem, with the homemade crosshair antenna, it works fine. No interference

Also, if i put the UHF antenna near the antenna tracker, it actually interferes enough to move the pan and tilt servos. Obviously it will never be that close, but its an interesting example of how much interference its throwing out.